Periytyvyysnäk

Periytyvyysnäk refers to the concept of heritability in Finnish. It is a statistical measure used in genetics to quantify the proportion of variation in a particular trait within a population that is attributable to genetic factors. In simpler terms, it estimates how much of the differences we see between individuals in a trait, such as height or a specific disease susceptibility, can be passed down from parents to offspring through genes.

Heritability is not a statement about the inevitability of a trait. A high heritability does not mean that a trait is fixed and cannot be influenced by environmental factors. Instead, it indicates the extent to which genetic differences contribute to observed differences in the trait within a specific population at a specific time. For example, if the heritability of intelligence is estimated to be high, it means that genetic differences account for a large portion of the variation in intelligence scores among people in that population. However, environmental factors like education and nutrition can still significantly impact an individual's intelligence.

It is important to distinguish between heritability in a broad sense and heritability in a narrow sense. Broad-sense heritability includes all genetic variation, including additive, dominance, and epistasis effects. Narrow-sense heritability, often denoted as h², focuses only on additive genetic variance, which is the component of genetic variance that can be predicted from the average effects of individual alleles. This narrow-sense heritability is particularly important in predicting the response to artificial or natural selection. Periytyvyysnäk is a fundamental concept in behavioral genetics and quantitative genetics, helping researchers understand the genetic basis of complex traits and diseases.